ABSTRACT Two related issues of great concern over the last decade globally are stress and employee performance. Gradually, it is becoming a universal problem that affects all sorts of workers, organizations, and countries. The study sought to assess stress and its effects on employee performance. A case study of Ecobank Ghana Limited-Sunyani. The objectives of the study were to: ascertain the nature of stress experienced by employees at Ecobank Ghana Ltd-Sunyani, determine the causes of stress at Ecobank Ghana Ltd-Sunyani and examine whether stress has any effect on employee performance at Ecobank Ghana LtdSunyani. Literature related to the study was reviewed. The researcher employed quantitative methods in gathering data from employees of Ecobank Ghana Ltd-Sunyani through a questionnaire. The data collected was analyzed by using tables, frequencies, pie charts, and bar graphs. The findings of the study indicate that, headache/ migraine, anxiety, depression, aches/pains, inability to concentrate, erratic moods, low self-esteem, and poor sleep patterns as the nature of stress experienced by bankers. Again, work Overload, large customer base, overstaying at the workplace, problematic customers, the riskiness of job, poor interpersonal relations with colleagues, and work environment were all causes of stress by bank employees. Feelings such as over tiredness, anger, frustration, irritation, helplessness,  and increased absenteeism cause employees to be inefficient. From this study, it is recommended that banks should adopt many ways to remove or reduce the stress and to counter the negative effects of stress among employees, guidance and counseling, quality consciousness awareness programs, psychological support should be provided to employees.